Magnetic resonance imaging (MRI) is an imaging method by which a nuclear spin in a subject placed in a magnetostatic field is magnetically excited with a radio frequency (RF) pulse at a Larmor frequency so that an image is generated from magnetic resonance signals generated due to the excitation.
In the field of magnetic resonance imaging, contrast enhancement by oxygen has been known. For example, an imaging method called the fluid attenuated inversion recovery (FLAIR) method has been known in which the time period between when an inversion pulse is applied and when the longitudinal magnetic component of cerebrospinal fluid (CSF) becomes zero is set as an inversion time (TI). It has been reported that the contrast of CSF changes when imaging is performed by the FLAIR method while oxygen is supplied.